In this paper, we study the problem of predicting the acceleration of a set of rigid, 3-dimensional bodies in contact with Coulomb friction. The nonlinearity of Coulomb's law leads to a nonlinear complementarity formulation of the system model. This model is used in conjunction with the theory of quasi-variational inequalities to prove for the rst time that multi-rigid-body systems with all con...

Simulation of dynamic systems possessing unilateral frictional contacts is important to many industrial applications. While rigid body models are often employed, it is well established that friction can cause problems with the existence and uniqueness of the forward dynamics problem. In these situations, we argue that compliant contact models, while increasing the length of the state vector, su...

Inverse Optimal Control (IOC) assumes that demonstrations are the solution to an optimal control problem with unknown underlying costs, and extracts parameters of these underlying costs. We propose the framework of Inverse KKT, which assumes that the demonstrations fulfill the Karush-Kuhn-Tucker conditions of an unknown underlying constrained optimization problem, and extracts parameters of thi...

Subsurface stress plays an important role in the damage of a movable contact element, but subsurface stresses are usually obtained with numerical calculation according to theory mechanics. In present paper, new method measure element is proposed using photoelastic technology. Although technology has been widely used measuring static state, it seldom moving body because observed point moving. Af...

We study the frictional behavior of both elastic and viscoelastic thin coatings bonded to a seemingly rigid substrate sliding against rough profile in presence Coulomb friction at interface. The aim is explore effect coupling between normal tangential displacement fields arising from finiteness material thickness quantify contribution this can have on energy losses. found that, due normal–tange...

The frictional properties of a rough contact interface are controlled by its area of real contact, the dynamical variations of which underlie our modern understanding of the ubiquitous rate-and-state friction law. In particular, the real contact area is proportional to the normal load, slowly increases at rest through aging, and drops at slip inception. Here, through direct measurements on vari...

Abstract The goal of this work is to evaluate the potential diamond-like carbon (DLC) coatings on thermoplastic polymers for friction and wear reduction in highly stressed rolling–sliding contacts. Therefore, hydrogen-containing DLC were deposited polymer surface by a low-temperature high power pulsed magnetron sputtering (HPPMS) physical vapor deposition (PVD) process. rolling-sliding contact ...

Multibody systems with rigid bodies and unilateral contacts are difficult to simulate due to discontinuities associated with gaining and losing contacts and stick-slip transitions. Methods for simulating such systems fall into two categories: penalty methods and complementarity methods. The former calculate penetration depths of virtual rigid bodies at every time step and compute restoring forc...

The kinetic (or sliding) friction of pharmaceutical tablets and capsules influences how they will behave during the conveying, coating, and packaging operations that are used for drug product manufacturing. In order to logically design equipment for manufacturing and packaging operations, and to simulate manufacturing and packaging performance (for example, using discrete or finite element mode...